Portable tool



June 2l, 1932,. J. R. HQFFMANA PORTABLE IrooL Filed Jan. 8. 1930 Patented June 21, 1932 UNITED STATES PATENT OFFICE g JOHN ROBERT HOFFMAN, F MADISON, WISCONSIN, ASSIGN OR TO MADISON-KIP? OOR- PORATION, 0F MADISON, WISCONSIN, A CORPORATION Ol' WISCONSIN PORTABLE TOOL Application led January 8, 1930. Serial No. 419,417.

My invention relates to portable tools and primarily to tools adapted to be driven by Huid pressure.

In prior art devices of this character, the working mechanism has generally consisted of many parts and theconstruction of the tool has been such as to make it unsuitable for one-hand manipulation. Many such devices have also been objectionable because of 1c their noisy operation or because they required special muling structure to reduce the noise.

In the device of my invention, the number of parts has been reduced to a minimum, and the construction so modified and im'- proved as to adapt it to use in one hand, without undue interference from the hose which supplies the fluid ressure for operating the turbine. ing 1s composed of only two parts andthe construction is such that the tool operates noiselessly without the provision of a special muilhng device.

The accompanying drawing illustrates one embodiment of my invention, and in this drawing,

Fig. 1 is a lon 'tudinal section of the complete device, t eI section being taken substantially on the line I-I of Fig. 2;

Fig. 2 is a section on line II--II of Fig. 1 showing the position of the iiuidA pressure inlet ports;

Fig. 3 is a section on line III-III of Fig. 1 showing the construction of the turbine runner and its relation to the casing;

Fig. 4 is a section on line IV-IV of Fig. 1 illustrating the inner construction of the exhaust casin Fig. 5 is aroken view on the line V--V of Fig. 1 showing the relation of one of the inlet ports to the runner; and

Fig. 6 is a section on line VI-VI showin the details of the fluid pressure control va ve.

Referring to the drawing, the reference character 7 designates a hollow casing having an elongated forward portion 8 and an enlarged rear portion 9. Preferably formed integrally with the casing 7 are a plurality of spaced radial ribs 10 and 11 Furt rmore the cas-v tends to the rear end of closure 12 and. contains a fluid pressure control valve 15.

The closure 12 also contains a duct 22 adapted to be at times connected with the chamber 13, and this duct is preferabl threaded to receive a short nipple 23, to whic pressure Huid from a suitable source may be supplied through a flexible hose 24. The nipple 23 and duct 22 are preferably angularly disposed with respect to the axis of the tool so as not to interfere with the manipulation of the control valve 15.

The valve 15, as best shown in Figs. 1 and 6, comprises a stem 18 terminating at its outer end in a handle 16. This stem 18 contains s.

duct 21 which is adapted, in one position of y the valve, to connect chamber 13 with duct 22. In rear of the duct 21, the stem 18 is reduced in diameter to receive a stop screw 19 which is threaded into the closure 12. A pin 20 passingldiametrically throuA h the stem 18 en ages t e stop screw 19 in oth the o an closed vpositions of the valve, the rotation of stem 18 being thereby limited to ap roximately degrees. The closure 12 is t readed at 17 to receive a packing 17a which prevents leakage of fluid from the' rear of the" valve.

The valve may be rotated by the handle 16.A

When the parts occupy the position shown in the drawin the end of duct 21 registers with the end of uct 22 so as to vconnect the source of pressure fluid with chamber 13, but upon rotation of handle 16 until pin 20 strikes stop `screw 19 on the op osito side from that shown, the openin o duct 22/is closed. It will be clear that y' suitably adjusting the handle 16 the amount of pressure fluid supplied to the tool may be regulated as desired.

The ribs 104 and 11 in casing 7 define annular spaces adapted to receive bearings 25 and 26 for a shaft 27. Bearing 25 has a reduced yes annular portion 25a and is lubricated by an oil cup 37. The bearing 26, however, contains a countersunk annular oil groove 26a on the inside adjacent to shaft 27. Groove 26a communicates with a small longitudinal' groove 266. When the tool is operating, the pressure fluid escaping through portion 8 of casing 7 forces oil along the shaft 27, and causes it to collect in grooves 26a and 26?) in sufficient quantity to lubricate the bearing.

The shaft 27 is rotatably mounted in these bearings and carries at its inner end a turbine runner 28. The inner end of shaft 27 also contains a conical seat 29 adapted to receive and support a ball bearing 30 which contacts with the front face of closurel 12 when this closure is secured in position. The forward end of shaft 27 carries a chuck 8 1 in which may be mounted any suitable tool 32, the shaft having flat portions 38 to which a wrench may be applied when chuck 31 is tightened or loosened. During normal operation of the tool, shaft 27 is supported by the bearings 25 and 26, but when the'tool 32 is forced against the work, ball bearing 30 contacts with the front face of closure 12 and forms a thrust bearing therefor.

The runner 28 carries on its rear surface a series of buckets 33 having their faces toward the inlet ports 35. The inner radial portions of buckets 33 are closed by an annular rim-like extension 34, so that ressure fluid cannot escape inwardly of the uckets, but is directed outwardly in the enlarged portion 9 of the casing. A runner construction of this general type is described and claimed in a copending application of Axel Pedersen, Ser. No. 563,202, filed September 16th, 1931 and entitled Pressure iiuid tools. It will be apparent that the runner 28, in combination with the ducts 14, comprises a simple single-action impulse turbine of the axialflow type. When any suitable source of Huid pressure, such as asource of compressed air, is connected to the hose 24 and the control valve 15 is moved to the open position as ,shown in Fig. 1, pressure fluid passes through the nipple 23, ducts 22 and 21, chamber 13, ducts 14 and ports 35, whence it is directed against the buckets 33 so as to set the runner 28 in motion and together with it, shaft 27 and tool 32.

The iuid after expending a substantial portion of its kinetic energy by impact against the buckets A33, escapes outwardly in a radial direction and then longitudinally of the casing 7 through the openings between the ribs 10, space 36 and between ribs 11 where it exhausts around the tool 32, so as to blow away any chips which are collected on the work during operation of the tool. Inasmuch as the runner 28 is mounted in over-hung bearings and the shaft 27 is of substantial length, the parts are well balanced and operate smoothly and with a minimum of vibration. When no axial thrust is being exerted on the tool 32, the entire weight of the rotating parts is carried b bearin 25 and 26, the axial thrust cause by the uid pressure impact being taken up by en agement of the runner 28 with the reduce rear face 25a of bearin 25. When, however, an axial thrust is rought to bear against tool 32, the ball bearing 30 resists it and reduces the resulting friction to a negligible amount.

It will be seen that th1s tool is composed of a very small number of parts and the speed of rotation of the runner 28 may be controlled readily by manipulation of the handle 16, so as to open or close the valve 15 and thus vary the amount of pressure iiuid which is brought to bear against the buckets 33. This tool is well adapted for one-hand operation and can be made in very small sizes. By making the nipple 23 very short and using a liexible hose 24, the iuid pressure inlet will not interfere appreciably with the handling of the device, the only need for another hand being to turn the control valve on or olf.

Another substantial advantage of this construction is that it operates noislessly without the provision of a muffler, the Huid pressure exhausted between the ribs 11, escaping in such manner that muflling devices are unnecessary.

The durability of the device is greatly enhanced by mounting the fluid pressure control valve directly in the rear closure so as to protect the operating parts from injury, and yet to render them readily laccessible for repair or replacement. Likewise the entire tool may be readily disassembled by removing the chuck 31 and then unscrewing the rear closure 12 so as to permit the runner 28 and associated parts to be removed.

This tool is well adapted for use as a pencil type of grinder, and as such may be employed advantageously in removing excess metal from small die-cavities or die-castings, as a dentists tool, and for numerous other uses which will be apparent to those skilled in the art to which this invention relates.

Subject matter disclosed in this case and not claimed herein, or in the Pedersen case referred to above, is claimed in my copending application, Ser. No. 548,245, filed July 1st, 1931, and entitled Hand tools Although I have herein shown and described only one form of portable tool embodying my invention, it will be obvious that various changes and modifications may be made, within the scope of the appended claims, without departing from the spirit and scope of my invention.

Vhat is claimed is:

1. A hand tool comprising a two-part casing; a turbine runner rotatably mounted in one of said parts, said one part containing a plurality of radial ribs forming longitudinal channels connecting the chamber adjacent said runner with atmosphere; and iiuid pres` sure controlling and directing means within the other of said parts.

2. A hand tool comprising an elongated casing; a turbine runner rotatably' mounted in said casin in overhung relation thereto;

l a plurality o spaced radial ribs on the interior of said casing and forming longitudinal channels around the mounting for the turbine runner; a closure member for said casa ing, said member having fluid pressure supply ducts therein; and a fluid pressure control valve within said closure.

3. A hand tool comprising an elongated casing containing a plurality of radial ribs defining. longitudinal channels terminating in exhaust ports and said casing havin a shaft mounted therein; a runner on sai shaft; a closure member for the rear end of said casing, said member containing pressure fluid ports in operative relation to said runner; and a fluid pressure control valve within said closure.

4. A iuid pressure operated tool comprising a two-part casing made up of an elon.-

gated portion, and a closure portion; a tur-V bine runner rotatably disposed in said elon'- gated portion; a plurality of radial ribsinsaid elongated portion and spaced to form pressure fluid exhaust channels; a pressure fluid control valve disposed within said closure portion, said portlon containin radial ducts adapted to supply pressure uid to said runner; and valve operating means on said closure portion.

5. A fluid pressure operated tool comprising` a two-part casing made up of an elongated portion and a closure portion, said elongated portion having one end enlar d and the other contracted; a plurality of ra 'al ribs disposed within said elongated portion and spaced to form iluid exhaust channels connecting said enlarged endv and said con.- tracted end; a turbine runner rotatably mounted in said enlar ed end; and fluid pres# sure controlling and dlrecting means disposed within said closure portion, saidY directin means being operatively associated with sai runner.

6. A fluid pressure operated tool comprising a hollow casing having one end enlarged and the other contracted; a shaft revolu ly mounted within said casing; a` turbine runner on said shaft within said enlar ed end; clutching means on said shaft adjacent to said contracted end; Aa plurality of radial ribs within said casing and s aced to form pressure fluid exhaust channe terminating adjacent said clutching means; a closure` member for said casin said member containing uid supply ucts terminating 1n ports adjacent to said runner; and a valve within said closure member, constructed and arranged to control the supply of pressure fluid to said runner.

7. In a fluid pressure operated tool; a casing; a bearing in each end of said casing; a turbine runner mounted in said casing in overhung relation to said bearings; a closure for said casing; luid ressure controllin and directing means wit in said closure, an adapted to supply kpressure fluid to said runner to operate the tool; means for lubricating one of said bearings from the outside of the casing; and lubricatin means on the other bearing constructed an arranged to have lubricant supplied to it by the escaping pressure fluid, when the tool is operating.

8. In a fluid pressure operated tool; a casing; a bearingin each end of said casing; a turbine runner mounted in said casing in overhung relation to said bearings;a closure for the casing adjacent to said runner; fluid pressure controlling and directing means within said closure; lubricating means on the bearing adjacent to said runner; and an oil collectlng groove in the other bearing, constructed and arranged to have lubricant supplied to it by the escaping pressure uid, when the tool is operating.

9. A fluid pressure operated tool comprising a hollow casing; a pluralit of spaced radial ribs in said casing, said ri s being cut away to form bearing'supports adjacent each end of the casing; a bearing in each of said supports; a turbine runner having a shaft rotatably supported in said bearings; and a closure member containing fluid pressure supply ducts for delivering pressure fluid to said runner.

10. A fluid pressure operated tool comprising an elongated casing; a turbine runner rotatably mounted in said casing; a plurality of spaced radial ribs forming longitudinal channels connecting the interlor of the casing adjacent to said runner with atmosphere, sald ribs being cut away to form bearin .receiving recesses for the mounting of sai runner; a closure member contaimng fluid pressure supply ducts terminating in ports adjacent said runner; and a pressure fluid controlling valve in said closure member.

In testimony whereof I have signed my name to this specification.

JOHN ROBERT HOFFMAN. 

